United States' Landon Donovan, controls the ball during a training session on Wednesday, May 14, 2014, Stanford, Calif. The US national soccer team kicked off its preparation camp at Stanford University preparing for the World Cup tournament, which gets underway in June. (AP Photo/Tony Avelar)

He has been the face of American soccer for more than a decade, but Landon Donovan says he's not sure he even has a place on the U.S. roster for the World Cup.

Probably the greatest player this country has produced, the 32-year-old forward for the LA Galaxy said Monday that there are no assurances that he'll take part in his fourth World Cup when coach Jurgen Klinsmann's team travels to Brazil next month.

Before a training session for the national team at Stanford, he said, "In '06 and 2010, I knew for the most part - unless I was awful - that I was going to make the team. This time is more similar to '02, when I wasn't sure.

"It's as competitive as it's been for me in a long time. There's a lot of quality here. You can really make the case for many of the guys here to be a part of the squad."

Choosing the 23-man roster from the current 30 players "is going to be a difficult decision for the coaches."

Reports that he and Klinsmann had a rift over his self-imposed sabbatical in 2013 were "not true," Donovan said. He said his relationship with the former World Cup forward from Germany is a typical player-coach relationship. He said Klinsmann "pushes us hard. He knows what it takes to be a world champion. None of us know that."

Donovan downplayed a lingering issue with his left knee that kept him out of the starting lineup in an exhibition against Mexico last month, saying, "It's OK."

He has been one of the fittest players in the camp, he said.

"I am very confident in my abilities," he said, "and I think I'm deserving to be part of the squad. But I have to prove that, and I have to earn that."

He's not the same player he was when he made his World Cup debut in Japan and South Korea, he said. As a rookie, he helped the U.S. advance from group play, and he scored in a second-round win over Mexico before the team lost to Germany in the quarterfinals.

"I don't have that youthful energy and excitement that I did in 2002, but I see the game and I see the situation a lot more clearly now," he said. "I think I'm more able to enjoy it that way. When you're younger, you're sort of going crazy trying to do whatever it takes to make the team, and you forget to enjoy it. Now I'm getting to enjoy it."

If Donovan's spot on the team is truly in doubt, starting goalkeeper Tim Howard said he would vote for him. "For me, it's a very easy equation," he said. "If Landon is on the field, he's our top one or two player. That's just my opinion. ... For me, he's easily one of our best players, and he strikes fear in our opponents."

One of the people pushing Donovan at forward is the Quakes' Chris Wondolowski. At 31, he's less than a year younger than Donovan, but he didn't make his national-team debut until 2011. He has scored nine goals for the U.S. in the past year, five of them in the CONCACAF Gold Cup.

"A lot of us obviously have been around him for a long time and think the path he has taken to get here is incredible," Donovan said, adding, "He's in really good form right now."

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